Yeah, you don't want to just copy stuff from the Internet, and especially you don't want to use only one source of information.
A good way to approach the project might be to first create what you think is a good outline for your writing project. Try writing as much about the subject as you can, within your outline, drawing only from what you already know. Resist the temptation to look up ANYTHING to confirm or deny your ideas. If you're not sure about some areas, make a stab at it anyway and even write what you THINK is true, even if you may have very little background on the subject. You'll learn and remember things from doing this when you later do the research and find truth or inaccuracy.
Also, think of some unlikely or unusual angles on the subject matter that will make an interesting way to present it. An anecdote, statistics, joke, or "what if" proposition are different ways to bring the reader into the subject. This is a good thing to do, too, if you know very little about the subject; at least you'll have your own unique framework and you'll have a starting point to begin writing.
The key is to come up with an original piece. It's all too common to start with research, find something "ideal" and then basically reproduce a writing that mirrors or follows the found article. And for heaven's sake avoid direct plagiarism. Absorb some information from research, spend some time away from the book or web page, and return to rewrite the material in your own words.
Then of course one wants to be critical and evaluate the authority of source information. Wikipedia is a case in point; since anyone can basically write anything to contribute to a wiki article, unless the material is source-referenced to an authority, a naming of Wikipedia as a source would be improper. In a school project, usually there is a requirement to name sources, so keep a good record.
I hope this helps. Best wishes!